Targeting Distribution Of Magnetic Nano-C3Tranferase Carrier Under External Magnetic Field After Injured Spinal Cord In Rats

[Objective]To explore the preparation method and biocompatibility of FITC loaded TAT-PEG-C3tranferase magnetic nano drug carrier (abbreviated by magnetic nano-C3tranferase carrier), to observe distribution targeting of drug carrier microsphere with additional magnetic field after spinal cord injury, and explore distribution of drug carrier microsphere with different time of additional magnetic field after spinal cord injury.[Method]Drug carrier microsphere were constructed by film scattered methods, and assessed by particle size,zeta potential,magnetic properties, drug release, observation by transmission electron microscopy; analysis cytotoxicity in vitro of drug carrier microsphere; cellular uptake analysis using fluorescence microscopy. Eighty-two rats SCI model were made and divided into5groups randomly.Group A(n=20), fluorescein isothiocyanate (FITC), group administered by caudal vein, Group B(n=20),drug carrier microsphere administered by caudal vein; Group C(n=20),drug carrier microsphere administered by caudal vein and external magnetic15min; Group D(n=12),drug carrier microsphere administered by caudal vein andexternal magnetic30min, Group E(n=10),drug carrier microsphere administered by caudal vein and external magnetic1h. Group A, B, Group A, B, C,D,E of respective selected and the tissus including liver,kindy spleen and T10spinal cord were harvested1h after administered by caudal vein,then the lipsome distribution in these was observed under fluorescence microscopy.10rats in Group A, B, C, D and E were respectively harvested spinal cord of the center of T10of4cm and were assayed iron in the spinal cord by flame atomic absorption spectrophotometry. Group D of2rats were harvested spinal cord, then observed the distribution of drug carrier microsphere under electron microscope.[Results]Drug carrier microspheres have good dispersion, with the saturation value of magnetization of63.5emu/g,and the carrier could maitain drug realease in vitro until day9;when co-culture with MCF-7cells,the average cell survival rate was78.10%;FITC flurescence density of Group C significant difference than Group A and B(P<0.05). The iron content in spinal cord of Group C were more than Group A and B(P<0.05), the iron content of Group E were more than Group C (P<0.05) determination of iron content in group D and group E was not significant (P>0.05).[Conclusion]We conclude that this novel magneticdrug carrier good biocompatibility and could act as a drug carrier, crossing the BSCB and targeting aggregation into cells in the spinal cord injury cite;30min applied additional magnetic field was the optimum time for aggregation of magnetic nano-C3tranferase carrier in CNS.